tbata sort of. The key formula to remember
To determine the total number of possible permutations of n given inputs you'll need 2n input combinations to test.
I've never seen the IB asks for more than 3 inputs. The grading for a truth table is kind of vicious because if you dont get all possible combinations, it immediately prevents you from getting full marks (even if you list three correct answers, if there are 9 possible permutations of the log, you will get zero marks).
Please click here for our wiki article on truth tables.